Biology Folio Biopract 2012

FORM 4

Name: Muhammad Solihin B. Kadir

No.Mak:29028

Chapter 3

Title: The movement of substances across a semi-permeable membrane

Aim: To study the movement of substances across the Visking tubing

Problem Statement: What factor influences the diffusion of substances through a semi-permeable membrane?

Hypothesis: The diffusion of molecules through a semi-permeable membrane is based on the size of the molecule

Variables:

Manipulated variable: Size of the solute molecules in the Visking tubing

Responding variable: Colour of the solution in Visking tubing Fixed variable: Time, volume of solutions and surrounding temperature

Material:

Benedict’s solution1% starch suspension

Iodine solution

30% glucose solution Distilled water

Apparatus:

Visking tubing, Cotton thread, Test tubes, BeakersWater bath (Bunsen burner, tripod stand & wire gauze)

Procedure:

1. Visking tubing is soaked in water for 30 minutes.2. One end of the Visking tubing is tied firmly with a piece of cotton thread to prevent

leakages.3. The Visking tubing is filled with 15ml of starch suspension by using a syringe.4. The other end of the Visking tubing is tied tightly with another piece of thread. The

colour of the solution in the Visking tubing is recorded.5. The outer surface of the Visking tubing is rinsed with distilled water. 6. 400ml of distilled water and 15ml of iodine solution are mixed in a beaker. The colour

of the solution in the beaker is record.7. The Visking tubing is immersed in the beaker of the solution and left stand for 30

minutesConclusionSmall-size molecules can diffuse easily through semi-permeable membrane but big sized molecules cant. The hypothesis is accepted.

Results

Original Colour Final Colour Benedict’s test

Visking tubing Colourless Blue-black Brick red Precipitate

Beaker Yellow Yellow Brick red Precipitate

Chapter 4

Title: Studying the effects of temperature on salivary amylase activity

Aim: To study the effects of temperature on salivary amylase activity

Problem Statement: What are the effects of temperature on salivary amylase activity?

Hypothesis: The rate of reaction catalysed by salivary amylase is highest at 37˚C / the optimum temperature for salivary amylase is 37˚C

Manipulated variable: Temperature of medium of reaction Responding variable: The rate of reaction catalysed by salivary amylase

Fixed variable: Volume of saliva, volume and concentration of starch suspension and pH of medium

Material:

1% starch suspension, Saliva suspension, Iodine solution, Ice cubes, and Distilled waterApparatus:

Beakers, Test tubes, Test tube rack, Syringes, Droppers, Glass rods, White tile with grooves, Thermometer, Bunsen burner, Tripod stand, Wire gauze, Stopwatch

Procedure1. A subject’s mouth is rinsed with distilled water. 10ml of subjects saliva is collected in

a beaker.10 ml of distilled water is added and mixture is stirred.2. A water bath at 20 C is prepared using water and ice cubes.3. 5ml of a 1% starch suspension is poured into a test tube. 2 ml of the prepared saliva

solution is poured into another test tube. Both test tubes are placed in the prepared water bath.

4. The test tubes are left in the water bath for 5 minutes.5. A drop of iodine solution is placed in each groove of a clean spotting tile.6. After 5 minutes, starch suspension is poured into a test tube containing the saliva

solution. The stopwatch is started immediately.7. A glass rod is use to stir the mixture vigorously. The test tube containing the mixture

is kept in water bath through the experiment.8. At one minute intervals for 15 minutes, a dropper is used to remove a drop of mixture

to be tested with iodine solution in one grooves of the spotting tile. The colour of mixture is noted.

9. Initially, the yellowish-brown colour of the iodine stain will turn to dark blue. With the increasing time, eventually the iodine test with come with no colour change. The time when this happens is recorded.

10. The experiment is repeated with water bath temperature of 30 C, 37 C, 50 C and 60 C.11. The rate of the reaction is calculated as the reciprocal of the reaction time. A graph

rate of the reaction against temperature is plotted.

Temperature of water bath Time for complete hydrolysis

Rate of reaction

0 No change after 20 minutes.

0

20 8 0.13

30 3 0.33

37 1 1.00

50 10 0.10

60 No change after 20 minutes.

0

Conclusion:From 0 C, as temperature increases, the rate of activity of salivary amylase increases until an optimum temperature of 37 C. After 37 C, further temperature increases decreases the rate of activity. The hypothesis is accepted.

Title: Studying the effects of pH on the activity of pepsin Aim: To study the effects of pH on the activity of pepsinProblem Statement: What are the effects of pH on the activity of pepsin?Hypothesis: An acidic medium at pH 3 is optimum for the activity of pepsinVariables

Manipulated variable: pH of medium Responding variable: Rate of reaction catalysed by pepsinFixed variable: Volume and concentration of albumen suspension, volume and concentration of pepsin solution and temperature of mediumMaterial

Egg albumen suspension, 1% pepsin solution, 0.1 M hydrochloric acid, 0.1 M sodium hydroxide solution, Distilled water

Apparatus

Beakers, Test tubes, Test tube rack, Droppers, Glass rodThermometer5 ml syringes, pH paper, Bunsen burner, Tripod stand, Wire gauze, Stopwatch

Procedure1. An albumin suspension is prepared by adding 1g of dried egg albumin to 100ml to

warm distilled water. The mixture is stirred and then strained to remove large undissolved particles.

2. A water bath is prepared at 37 C by mixing tap water with some hot water. This temperature must be maintained throughout the experiment.

3. 5 ml of 1% albumin is poured into a test tube. The test tube is placed in water bath.4. 2 ml of 1% pepsin solution and 5 ml of pH 1 buffer solution are poured into another

test tube. The test tube is placed in water bath.5. Both test tubes are left in water bath for 5 minutes.6. After 5 minutes, the albumin suspension is poured into the test tube containing the

mixture of pepsin and buffer solutions. A glass rod is used to stir the mixture vigorously.

7. The stopwatch is started immediately.8. The time for the cloudy pepsin solution to become clear when the albumin has been

completely hydrolysed is noted. 9. Steps 2-8 are repeated using buffer solution of pH1, 2, 3, 4 and 5.10. The rate is calculated.

pH Time (minutes)

Rate of reaction

1 1.0 1.00

2 0.5 2.00

3 1.0 1.00

4 3.0 0.33

5 6.5 0.15

Title: Studying the effects of substrate concentration on salivary amylase activityAim: To study the effects of substrate concentration on salivary amylase activityProblem Statement: What are the effects of substrate concentration on salivary amylase activity?Hypothesis: The rate of enzymatic reaction increases with the increase in substrate concentration until it reaches a maximum rateVariables: Manipulated variable: Substrate concentration / Concentration of starch suspension Responding variable: Rate of reaction / Time taken for the hydrolysis of starch to be

completedFixed variable: Enzyme concentration, pH of medium, volume of starch, volume of saliva suspension and surrounding temperatureMaterial: Syringes White tiles with grooves Test tubes Glass rod Dropper Measuring cylinder Stopwatch Beaker Thermometer Water bath (Bunsen burner, tripod stand and wire gauze)

Procedure 1. A 1% albumin solution is prepared by adding 1g of dried egg albumin to 100ml of

warm distilled water. Stir the mixture then strain it remove undissolved particles.2. The 1% albumin suspension is diluted to procedure the following concentrations3. The rate reaction is calculated as albumin concentration against reaction of time. A

graph of rate of reaction against albumin concentration is plotted.

Chapter 5

Title: Preparing a slide of onion root tip to identify the various stages of mitosis

Aim: To prepare and observe a slide of onion root tip to identify the various stages of mitosis

Material: Aceto-orcein stain / acetic orcein stain 1 M hydrochloric acid Onion bulb Distilled water

Apparatus:Petri dish, Watch glass, Blade / Scalpel, Mounting needles, Toothpicks, Beaker, Bunsen burner, Microscope, Glass slides, Cover slips, Filter papers

Procedure:1. Prepare a slide of onion root tip by using the aceto-orcein stain / acetic orcein stains

the chromosomes2. Observe the slide of onion root tip to identify the various stages of mitosis by using

light microscope

Chapter 6Title: Determining the energy value in food samplesAim: To determine the energy value in food samplesProblem Statement: Which food sample has a higher energy value?Hypothesis: Cashew nut/ Walnut has a higher energy value that groundnutVariables: Manipulated variable: Type of food sample Responding variable: Energy value of food samples Fixed variable: Mass of water and mass of food sample

Material: Peanut (whole) Plasticine Cotton wool Distilled water

Apparatus: Boiling tube, Thermometer (0 – 100˚C) Pin (5 – 8 cm), Bunsen burner, Retort stand and clamp, Wind shield, Electronic balance

Procedure: 1. A fresh groundnut is weighed with an electronics weighing scale and its mass

recorded.2. 20 ml of distilled water is added to a boiling tube.3. The boiling tube is clamped to a retort stand in vertical position.4. The initial temperature of water in the boiling tube is recorded5. The groundnut is fixed to the pointed end of a long pin. The other end of the pin is

poked into a piece of plasticine.6. The groundnut is ignited with a match and immediately placed under the boiling tube.7. As the water in the boiling tube is heated up by the flame of the groundnut, the water

is stirred gently with a thermometer to distribute the heat evenly.8. The final temperature of water is recorded.9. The energy value of the groundnut is calculated.10. Repeat step 1-9 using a cashew nut.

Result:Food Sample Groundnut Cashew nutMass(g)Initial temperatureFinal temperatureRise in temperature

Title: Determining the vitamin C content in various fruit juicesAim: To determine the vitamin C content in various fruit juicesProblem Statement: Do different types of fruit juices contain similar amounts of vitamin C?Hypothesis: Lime juice contains a higher concentration of vitamin C compared to pineapple juice and orange juice. Variables: Manipulated variable: Types of fruit juices Responding variable: Volume of fruit juice needed to decolourise DCPIP solution Fixed variable: Volume of DCPIP solution and standard concentration of ascorbic

acid solution

Material: 1.0% dichlorophenolindophenol (DCPIP) solution 0.1% ascorbic acid solution Freshly prepared lime juice Freshly prepared pineapple juice Freshly prepared orange juice

Apparatus: Specimen tubes 1 ml syringe 5 ml syringes with needles 50 ml beakers Gauze cloth Knife / Scalpel

Procedure1. 1 ml of DCPIP solution is added to a test tube by using a syringe labelled D (D for

DCPIP).2. 5 ml of 0.1% ascorbic acid is sucked into another syringe, labelled A (A for ascorbic

acid).3. The needle of syringe A is dipped into the DCPIP solution. The 0.1% ascorbic acid in

the syringe is released a little at a time into the DCPPIP solution. While releasing the ascorbic acid, the test tube is swirled gently.

4. The volume of 0.1% ascorbic acid needed to decolourise the DCPIP is recorded.5. Steps 1 to 4 are repeated using freshly prepared lime juice and pineapple juice instead

of 0.1% of ascorbic acid.6. The percentage and concentration of vitamin C in each fruit juice are calculated using

following formula.

Conclusion

Lime juices have higher vitamin C content than pineapple juice. Hypothesis is accepted.Title: Planning and conducting an experiment to study enzyme action on starch

Aim: To study enzyme action on starch

Problem Statement: How does the enzyme in saliva act on starch?

Hypothesis: The enzyme is saliva digest starch into a reducing sugar / the enzyme in saliva hydrolyses starch into a reducing sugar

Variables: Manipulated variable: Absence or presence of salivary amylase and starch Responding variable: Presence of reducing sugar Fixed variable: Temperature at 37˚C, starch concentration and volume of mixture

Material1% starch suspension, Benedict’s solution, Iodine solution, Saliva suspension, Distilled water

Apparatus10 ml pipette and 500 ml beaker

Procedure1. The mouth is rinsed and the saliva is collected.2. Two test tubes, labelled A and B are each filled with 5 ml starch solution.3. Using a long dropper, 1ml of starch solution is taken out from each test tube and

Benedict’s test is carried out. The result is recorded.4. 2 ml of the saliva is then added into test tube A. To test tube B, 2ml of distilled water

is added.5. After 30 minutes, steps 3 and 4 are repeated. the results are recorded in a table

ResultsTest Tube Content Results of tests at the

beginning of the experiment

Results of test after 30 minutes

Iodine test Benedict test

Iodine tests Benedict’s Test

A 2ml saliva +5 ml starch solution

B 2ml distilled water + 5 ml starch solution

Conclusion: Reducing sugar is produced when starch is digested by salivary amylase. The hypothesis is accepted.

Title: Planning and conducting an experiment to study the enzyme action on a protein food sample

Introduction: Albumen does not dissolve completely in water Albumen suspension is milky in nature. After albumen is fully digested, the

suspension becomes clear Pepsin requires an acidic pH of about 2 to act at maximum rate

Aim: To study the enzyme action on a protein food sample

Problem Statement: How does the enzyme acts on protein?

Hypothesis: The test tube contains albumen and pepsin solution becomes clear at the end of the

experiment An acidic medium is needed for protein digestion by pepsin

Variables: Manipulated variable: Absence or presence of pepsin in albumen Responding variable: Cloudy or clear (clarity of contents) albumen suspension after

20 minutes Fixed variable: Concentration and volume of albumen, concentration and volume of

pepsin (enzyme), concentration of hydrochloric acid, surrounding temperature at 37˚C

Material:Albumen (egg-white) suspension, dilute hydrochloric acid, Pepsin suspension, Distilled water

Apparatus10 ml pipette, 500 ml beaker, Test tubes, Test tube rack, Droppers, Thermometer, Stopwatch, Water bath (Bunsen burner, tripod stand and wire gauze)

Procedure1. Two test tubes are labelled and filled as follows: X: 2ml pepsin solution+5 ml albumin solution+3 drops of HCL acid Y:2ml pepsin solution+5ml albumin solution+3 drops of NaOH2. The apparatus is set up3. The appearance of the liquid in each test tube, clear or cloudy, is observed at the

beginning of the experiment.4. After 30 minutes, the condition of the liquid in each test tube is observed again.5. The observation recorded in a table.

Results:Test tube Content Appearance of the

beginningliquid in test tubeafter 30 minutes

X Pepsin +Albumin + Acid

Y Pepsin + Albumin +Alkali

Conclusion:

The digestion of the albumin protein occurs in the acidic medium but not in the alkaline medium. This means pepsins are active in an acidic medium but inactive in alkaline medium. The hypothesis is accepted.

Title: Studying the effects of macronutrient deficiency in plants

Aim: To study the effects of macronutrient deficiency in plants

Problem Statement: What are the effects of macronutrient deficiency in plants? / Do macronutrient deficiency have any effects on plant growth and development?

Hypothesis: Plant grows healthily in a complete Knop’s solution. Macronutrient deficiencies affect plant growth and development.

Variables: Manipulated variable: Components of minerals in culture solution Responding variable: Growth of the seedling / Condition of the plants Fixed variable: Volume and concentration of solution, size and type of maize

seedlings, amount of air that is pumped into the jar, amount of sunlight, surrounding temperature

Material:Maize seedlings, Potassium nitrate (KNO3), Potassium dihydrogen phosphate (KH2PO4), Magnesium sulphate (MgSO4), Calcium nitrate (Ca (NO3)2), Ferum (III) phosphate (FePO4), Cotton wool, Black paper Distilled water

Apparatus: Glass jars, Rubber bungs with holes, Straight glass tubes to fit into the holes of the rubber bungs, L-shaped delivery tubes to the connected to a vacuum pump, Knife

Procedure:1. Eight gas jars are labelled A to H respectively.2. The gas jars are filled with various culture solutions, as shown as table below.

Gas jar Composite Culture solutionCalcium nitrate(o.8g)

Potassium nitrate(0.2g)

Potassium dihydrogen phosphate(0.2g)

Magnesium sulphate(0.2g)

Ferum(III)Phosphate(traces)

Distilled water 100ml

A(Distilled water only)B(complete Knops’ solutions)C(without nitrogen)

Calcium chloride

Potassium chloride

D(without Phosphorus)

Potassium chloride

Ferum(III)nitrate

E(without sulphur)

magnesium chloride

F(without potassium)

Sodium nitrate

Calcium phosphate

G(without calcium)

Sodium nitrate

H(without magnesium)

Potassium sulphate

3. The sides of all gas are covered with black paper to prevent light from reaching the culture solutions to prevent algae growth.

4. The seedlings are exposed to light of the same intensity so photosynthesis can be carried out

5. The culture solutions are aerated to supply oxygen for the respiration roots.6. The culture solutions are replaced every week as some nutrients would have been

used up by the seedlings.7. After one month, the condition of each seedling is observed.

Gas jar Deficient in Effects of deficiencyA All nutrientsB noneC nitrogenD phosphorusE sulphurF potassiumG calciumH magnesium

Conclusion: plants do not grow healthily and show various deficiency symptoms if they are deficient in macronutrients. The hypothesis is accepted.

Title: Investigating the effect of light intensity on the rate of photosynthesis

Aim: To investigate the effect of light intensity on the rate of photosynthesis

Problem Statement: How does light intensity affect the rate of photosynthesis?

Hypothesis: The higher the light intensity, the higher the rate of photosynthesis Variables: Manipulated variable: Distance between light source and plant Responding variable: Number of bubbles released in five minutes (rate of

photosynthesis) Fixed variable: Type and size of plant, percentage of sodium hydrogen carbonate

solution and voltage of bulb

Material: A few sprigs of Hydrilla sp., 1% sodium hydrogen carbonate solution, Plasticine, Distilled water

Apparatus:Light source (60 W bulb),500 ml beaker, Test tube, Glass filter funnel, Stopwatch, Thermometer, Meter rule, Razor

Procedure:1. The apparatus is set up as shown.2. The light bulb is placed at a distance of 50 cm from the beaker containing Hydrilla.3. The temperature of the water bath is maintained at 28 C. A little sodium hydrogen

carbonate is dissolved in water to provide carbon dioxide to Hydrilla.4. The light bulb is on.5. When the Hydrilla begins to release gas bubbles constantly, the stopwatch is turned

on.6. The number of gas bubble released in one minute is recorded. 7. Two more readings are taken and the average number of bubbles per minute is

calculated.8. Steps 6-7 are repeated again with light bulb at distances of 40 cm, 30 cm, 30 cm, and

10 cm from Hydrilla.9. A graph of number bubbles per minute versus the distance of light from Hydrilla is

plotted.

Results:Distance of light bulb from Hydrilla (cm)

10 20 30 40 50

Number of bubbles per minutes

Conclusion: the rate of photosynthesis increases with the light intensity. The hypothesis is accepted.

Solid Pollutants in the Air of Different EnvironmentAim: To compare solid pollutants in the air of different environments

Problem Statement: Does the air of different environments contain the same amount of solid pollutants?

Hypothesis: The air of different environments does not contain the same amount of solid pollutants.

Variables:Manipulated variable: Air from different environments

Responding variable: Amount of solid pollutants present

Fixed variable: Time and size of cellophane tape

Materials: Cellophane tape

Apparatus: slides, a Petri dish and a microscope

Technique: Observe the amounts of solid pollutants with a microscope

Procedure : 1) Prepare 5 slides and label A, B, C, D and E2) Stuck a piece of cellophane tape with the adhesive surface facing upwards on each slide3) Place the slides at 5 spots in 5 different types of environmentsa) Slide A in a closed Petri dishb) Slide B attached to a lamp post in a car parkc) Slide C in an open fieldd) Slide D in a classroome) Slide E in an air conditioned room4) Left all slides aside for a week5) Collect all slides after a week and view each slide under a microscope using a low power6) Record the observations

Results :

slides place observationA Closed Petri dish B Lamp post in a car park C Open field D Classroom E Air-conditioned room

Conclusion : The air in the car park is the most polluted compare to the closed Petri dish ,open field, classroom and air-conditioned room. The hypothesis is accepted

Level of Water Pollution in Several Samples of Water

Aim: To investigate the level of water pollution in different sources of water

Problem Statement: What is the level of water pollution in different sources of water?

Hypothesis: River water is the most polluted of the samples of the water collected

Variables:

Manipulated variable: water samples from different sources.

Responding variable: Time taken for methylene blue solution to decolourise

Fixed variable: Volume of water sample, size of reagent bottles, concentration and volume of methylene blue solution

Materials: Methylene blue solution (0.1 %), water samples (from a river, a pond, a drain, a pipe, a well and distilled water)

Apparatus: 250 ml reagent bottles with stoppers, beakers, syringes and a stopwatch

Technique: Measure and record the time taken for the methylene blue solution to decolourise by using a stopwatch

Procedure :1) Collect water samples from 5 different sources2) Label the reagent bottles P, Q, R, S, T, U3) Fill the reagent bottles with the following samplesP : Pipe waterQ:Drain waterR:River waterS:Pond waterT:Well waterU:Distilled water

4) Close the reagent bottles with a stopper

5) Test all the water samples on the same day

6) Add 1 ml of methylene blue solution to the base of each water sample using a syringe

7) Close the reagent bottles quickly. Do not shake the bottlePlace all the bottles in a dark cupboard and the stopwatch is activated

9) Examine the bottles from time to time

10) Record the time taken for the methylene blue solution to decolourise for all the water samples

11) Record the results in a table.

ResultsReagent bottle Water sample Time taken for methylene blue to decolourise (hour)P Pipe water Q Drain water R River water S Pond water T Well water U Distilled water

Conclusion : The methylene blue solution took the shortest time to decolourise river water. River water is the most polluted. The hypothesis is accepted

Aim / Objective of the StudyTo investigate the process of anaerobic respiration in yeast

Problem StatementWhat are the products of fermentation?

HypothesisIn the absence of oxygen, yeast undergoes anaerobic respiration to produce carbon dioxide, ethanol and energy

Variablesa) Manipulated variable: Presence of yeastb) Responding variable: Changes on lime water and temperaturec) Fixed variable: Anaerobic condition

Material5% yeast suspension, 5% glucose solution, paraffin oil & lime water

ApparatusBoiling tubes, test tubes, thermometers, stoppers with delivery tubes, measuring cylinders & beaker

Procedure

1. One third of the boiling tube is filled with 5% glucose solution which has been boiled and then left to ccol down.

2. The boiling tubes are labeled A and B3. A small amount of yeast is put into boiling tube A4. Paraffin is then added to both boiling tubes5. The apparatus is set as shown in the diagram with the ends of the delivery tube

immersed in boiling tube filled with 2ml of lime water6. The apparatus is left aside for 1 hour7. The initial temperature is recorded8. At the end of the experiment, the final temperature is recorded and the condition of

the lime water and the smell of the solution in the boiling tubes are recorded

Draw pic here

Results

Boiling tube Temperature initial (Celsius)

Temperature final (Celsius)

Condition of lime water

Smell of the solution

AB

Aim / Objective of the StudyTo investigate the difference between inhaled and exhaled air in terms of oxygen and carbon dioxide contents

Problem StatementAre the contents of oxygen and carbon dioxide in inhaled air the same as those on exhaled air? / does inhaled air contain the same amount of oxygen and carbon dioxide as exhaled air?

HypothesisInhaled air has a higher percentage of oxygen when compared to exhaled air. Exhaled air has a higher percentage of carbon dioxide when compared to inhaled air.

Variables

a) Manipulated variable: Inhaled air and exhaled airb) Responding variable: Percentages of oxygen and carbon dioxidec) Fixed variable: Method of analysis

MaterialPotassium hydroxide solution, water & potassium pyrogallate solution

ApparatusJ-tube, boiling tubes, rubber tubing, ruler & basin

Procedure

Draw pic here

1. The screw if the J-tube is turned clockwise until the end2. The end of the J-tube is placed in water and screw is turned anticlockwise to draw a

length of 5cm of water into the J-tube3. The J-tube is removed from the water.4. The screw is turned anti clockwise to draw about 10cm of air column (inhaled air)

into the J-tube5. The end of the J-tube is placed in the water again and little more water is drawn into

the J-tube to trap the air column in the J-tube6. The screw is adjusted so that air column is in the middle of the J-tube7. The J-tube is then immersed in the basin of water for 2 minutes to stabilise the

temperature of air column8. The length of the air column is measured in the basin of water by ruler. The length of

the air column is recorded in cm

9. The screw is turned clockwise to remove some water in the J-tube so that the air column has 2-3 mm from the end of the tube labeled A

10. The end of the J-tube is then immersed in potassium hydroxide solution and the screw is turned anti clockwise to draw about 2-3cm of the solution into the J-tube.

11. The tube is removed from the solution and the screw is used to move the potassium hydroxide column to and fro several times so that it can absorb the carbon dioxide trapped in the air column

12. Steps 7-8 are repeated. The length of the air column is then measured and recorded as b cm

13. The screw is turned clockwise to remove the potassium hydroxide solution until 2-3mm is left at the end of the tube.

14. Step 10 is repeated by using alkaline potassium pyrogallate solution to absorb oxygen from the air column

15. The tube is removed from the solution. The alkaline potassium pyrogallate column and air column in the tube are moved to and fro by adjusting the screw

16. Steps 7-8 are repeated. The length of air column is measured and recorded as c cm17. Based on the results, the percentage of carbon dioxide and oxygen in the sample oh

inhaled air column are calculated18. The experiment is repeated using exhaled air. Sample of exhaled air can be prepared

in the following ways:

Draw pic here

a) Air is blown into the plastic drinking straw to get rid of all the air in the strawb) The straw is then placed in a test tube full of water. Air is blown into the straw to

collect a sample of exhaled airc) The composition of oxygen and carbon dioxide in the exhaled air is determined using

the same procedure as in steps 1 to 17d) The results are recorded and calculated as shown in the table

ResultsMeasurement Inhaled air Exhaled airLength of air column (cm)Length of air column after adding potassium hydroxide solution (cm)Length of air column after adding alkaline potassium pyrogallate solution (cm)Length of carbon dioxidePercentage of carbon dioxideLength of oxygen in the air columnPercentage of oxygen

Aim / Objective of the StudyTo study the effects of vigorous exercise on the breathing and heartbeat rates

Problem Statement

What is the effect of vigorous exercise on the breathing and heartbeat rates?

HypothesisVigorous exercise increases the breathing and heartbeat rates

VariablesManipulated variable: Resting or vigorous exerciseResponding variable: Breathing rate and heartbeat rateFixed variable: The type and duration of exercise, gender and age of the students

ApparatusStopwatch, spirometer, stethoscope

Procedure1. Four students are involved in this experiment2. Each students is asked to measure the rate of breathing and the rate of heartbeat by

using spirometer and the stethoscope respectively in the following condition:a) At restb) After the vigorous exercise such as running ot going up and down staircase

for two minutes(the rate of heartbeat can also be measured by taking the pulse rate)

3. The rate of breathing and the rete of heartbeat at rest and after vigorous activity is recorded

ResultsStudent Rate of

breathing(breaths per minute) at rest

Rate of breathing(breaths per minute) after vigorous activity

Rate of heartbeat or pulse rate(beats per minute) at rest

Rate of heartbeat or pulse rate(beats per minute) after vigorous activity

ABCD

TitleDemonstrating the effects of cigarette smoke on lungs

Aim / Objective of the Study

To show the effects of cigarette smoke on lungs

Problem StatementWhat are the effects of cigarette smoke on lungs?

HypothesisCigarette smoke corrodes the cotton wool to change colour and contains acidic gas.

MaterialCotton wool, universal indicator & cigarettes

ApparatusU-tube, thermometer, boiling tube, retort stand and clamp, filter pump & rubber tubing

Procedure1) The apparatus for collecting some of the substances in cigarette smoke is set up as

shown in diagram2) The initial temperature before the experiment begins is recorded3) The cigarette is lighted and the suction pump is switched on4) The change in colour of the cotton wool, bicarbonate indicator and the temperature of

the temperature is observed and recorded after the cigarette has stopped burning

ResultsColour of cotton wool

Colour of bicarbonate indicator

Temperature (Celsius)

Beginning of the experiment

White Red 30

End of experiment Brown Yellow 60

Aim / Objective of the StudyTo study the intraspecific and interspecific competitions in plants

Problem Statement

How do intraspecific and interspecific competitions affect the growth of maize and rice plants?

HypothesisIntraspecific competition occurs between plants of the same species. Interspecific competition occurs between plants of different species. / The greater the competition among the seedlings, the greater the effect on the height of the seedlings.

Variables

Manipulated variable: Types of seedlingsResponding variable: Dry mass of seedlings / Height of seedlingFixed variable: Quantity and types of garden soil, amount of water, intensity of sunlight, distance between each seedling and number of seedlings

MaterialThree seedling trays (2 m x 1 m each) with garden soil, a packet of maize seeds, a packet of paddy seeds & distilled water

ApparatusRuler, oven, electronic balance, spade , waterproof paint & paintbrush.

Procedure1. Three seedlings trays are filled with same amount of garden soil and labeled plot A, B

and C.2. The initial mass of seedling are recorded3. The seedling are planted with the distance of 5cm between each seedling4. The seedling in each tray are watered daily with the same amount of water and left to

grow5. After 30 days, 10 paddy plants are picked at random and removed from tray A. The

plants are washed to remove the soil from the roots6. The plants are then dried in an oven at 100-105 Celsius 7. The dry mass of paddy plants are weighed and recorded using an electronic balance8. The average dry mass of paddy plant is recorded9. Step 5 is repeated for plots B and C (10 paddy plants and 10 maize plants)10. Data is recorded in a table

Plot Average dry mass of plants (g) Change in dry mass (g)

Paddy Maize Paddy Maize

Initial Final Initial Final

A(paddy) B(maize)

C(paddy and maize)

Aim / Objective of the StudyTo estimate the population size of garden snails using capture, mark, release and recapture technique

MaterialA bottle of Indian ink / A non-poisonous and waterproof ink

ApparatusHammer, paintbrush, pen & notebook

Procedure1. An area in the field was chosen as the place for the field study2. A large number of garden snails were caught in the first sample and the number was

recorded as x3. Each garden snail that were caught and marked on it shells using India ink4. All the garden snails that were caught and marked were then set free5. After 3 days, the garden snails were caught again at random in the same place for

field study. The number of garden snails caught in the second sample was recorded as y

6. From the second sample caught, the number of garden snails that were marked were counted and recorded as z

7. The population size of the garden snails was estimated by using the following formula

x= number caught in first sampley= number caught in second samplez= number of marked in the second sample

Population size = xyz

ResultsNumber of garden snails Estimated

populationNumber caught in first sample

Number caught in second sampleNumber caught Number marked

x y z xy/z

Aim / Objective of the StudyTo investigate the distribution of plants using the quadrats sampling technique

MaterialPen

ApparatusA quadrat measuring 1 m x 1 m & notebook

Procedure1. The school field was chosen as the place for field study2. Quadrats size 1m x 1m are used3. The area covered by plants in the school field were chosen 4. Three types of plants in the school field were chosen5. The quadrats were set up at random6. For each quadrat, the area of coverage of each plant species were calculated7. The number of individual plant species in each sample or quadrat was counted8. The area coverage and number of individual plant species studied in each quadrat

were recorded in a table9. Each species that can be found in the quadrat was ticked in the results table to show

the frequency10. The percentage coverage, density and frequency for each plant species were

calculated and recorded in the table

ResultsPlant species

Area of coverage in the quadrant for each species Total area of coverage

Percentage coverage (%)

1 2 3 4 5 6 7 8 9 10

A

B

C

Plant species

Number of individual plants species in the quadrant Total number of individual plant species

Density

1 2 3 4 5 6 7 8 9 10

A

B

C

Plant species

Frequency Total number of frequency

Percentage frequency (%)

1 2 3 4 5 6 7 8 9 10

A

B

C

AimTo show the effect of pH and light intensity on the population growth rate of an organism

Problem StatementWhat are the effects of the pH level and light intensity on the population growth of Lemna sp.?

HypothesisA pH value that is neutral or nearly neutral is most suitable for the population growth of Lemna sp.

VariablesManipulated: pH valueResponding: Number of leaves in a quadrat (100x100cm)Constant: Light intensity, temperature

ApparatusQuadrat frame size (100x100cm)

MaterialsLemna sp., culture solution, hydrochloric acid, sodium hydroxide

Procedure1. Ten Lemna sp. Plants were grown in a small basin containing litre of culture

solution.2. Three sets of apparatus were set up and labeled as P.Q and R3. In sets, 100 ml of hydrochloric acid was added to the culture solution. In set Q,

100ml of sodium hydroxide was added while set R only contained the culture solution in a neutral condition

4. For each set, a quadrat frame with an area of 100x100cm was placed over the Lemna sp. Plants

5. The number of leaves in the quadrat was counted for each sat of apparatus6. The results were then left aside for a week7. After a week, the number of leaves in the quadrat for each set of apparatus8. The results were then recorded in atable9. The three sets were left aside for a week10. After a week, the number of leaves in the quadrant for each set of apparatus were

counted and recorded

ResultspH of the solution Set p(acidic) Set Q(alkaline) Set R(neutral)Number of leaves per 100x100cm at the beginning of the experimentNumber of leaves per 100x100cm at the end of the experiment

AimTo show the effect of abiotic components on the activities of microornganisms

Problem statementWhat is the effect of temperature, pH value, light intensity and nutrients on the rate of anaerobic respiration in yeast?

Hypothesis1. The activity of yeast at a temperature of 37 Celsius2. The activity of yeast is optimum in acidic medium3. The activity of yeast is higher at a lower light intensity4. The activity of yeast is affected by the presence of nutrients

VariablesAbiotic component Responding Manipulated Kept constantTemperature Time taken for lime

water to turn cloudyTemperature Volume of yeast

suspensionpH value Time taken for lime

water to turn cloudypH value Volume of yeast

suspensionLight intensity Time taken for lime

water to turn cloudyLight intensity Volume of yeast

suspensionnutrients Time taken for lime

water to turn cloudyPresence of nutrients(glucose)

Volume of yeast suspension

ApparatusThermometer, 60 watt bulb, boiling tubes with delivery tube, test tubes & stopwatch

MaterialsYeast suspension, hydrochloric acid(1 M), sodium hydroxide solution(1 M), glucose solution, distilled water, lime water and water bath 5,40 & 70 Celsius.

Procedure1. Ten boiling tubes were labeled A to J2. Boiling tubes A to C were filled with 10 ml yeast suspension and 10 ml boiled

glucose solution and covered with a layer of paraffin3. Boiling tubes A to C were placed in the water bath at temperature 5, 40 & 70 Celsius

respectively for 5 minutes4. After 5 minutes, when the yeast and glucose solution has reached the required

temperature, the delivery tube is connected to the test tube containing lime water5. The time taken for the lime water turn cloudy was recorded6. Three boiling tubes labeled D, E and F were set up as follow:

a. Boiling tube D: 10 ml yeast suspension +10 ml boiled glucose solution+ 2ml hydrochloric acid

b. Boling tube E: 10ml yeast suspension +10 ml boiled glucose solution+ 2ml sodium hydroxide solution

c. Boling tube F: 10ml yeast suspension +10 ml boiled glucose solution+ 2ml distilled water

7. Boiling tubes D, E and F were kept at 37 Celsius8. For each boiling tube, the time taken for the lime water to turn cloudy was recorded9. Two boiling tubes G and H were filled with 10 ml of yeast suspension and 10 ml of

boiled glucose solution each. Both boiling tubes were kept t 37 Celsius. Test tube G was placed near the lighted bulb while boiling tube H was kept in the dark. For each boiling tube, the time taken for the lime water to turn cloudy was recorded

10. Two more boiling tubes, labeled I and J, were filled with 10ml of yeast suspension each. In boiling tube I, 10 ml of boiled glucose solution was added while in boiling

tube J, 10 ml of distilled water was added. Both boiling tubes were kept at 37 Celsius. For each boiling tube, the time taken for the lime water to turn cloudy was recorded

ResultsAbiotic factor studied

Boiling tube

Content of boiling tube Abiotic condition

Time taken for lime water to turn cloudy

Temperature A

B

C

pH value D

E

F

Light intensity G

H

Nutrients I

J